ENG10004: Building an Earthquake Resistant Structure Project Report

This report presents a project undertaken by a student to design and build a prototype of an earthquake-resistant structure. The project involved a group effort to develop a tower using balsa wood, strings, and provided materials, including a motor, accelerometer, sandbags, and a shake table. The design process followed engineering design principles, focusing on meeting specific requirements such as base area, lightweight construction, and the ability to withstand simulated seismic activity. The report details the design problems encountered, such as generating sinusoidal wave movements and coding challenges. It highlights the background research on earthquake frequency and building design, with a focus on base isolation techniques. The final design solution involved isolating the tower from the base platform. The analysis section presents experimental results, including the effects of varying live loads and acceleration rates on the tower's stability and deformation. The conclusion emphasizes the effectiveness of base isolation in mitigating earthquake effects, with recommendations for further improvements. The report also includes reflective journal entries detailing the student's learning experience throughout the project.

Faculty of Science, Engineering and Technology
ENG10004
Digital and Data Systems
Project Report
Student Name:
Student ID:
Date:

ENG10004 Digital and Data Systems – Project Report
Self-Assessment Details
The following table provides my self-assessment for my individual contributions to the project.
Few
(0-49)
Minor
(50-59)
Important
(60-69)
Major
(70-79)
Major
&Leadership
(80-100)
Self-
Assessment
(please tick)     
Declaration
I declare that this report is my individual work. I have not copied from any other student’s work
or from any other source except where due acknowledgment is made explicitly in the text, nor
has any part of this submission been written for me by another person.
Signature:
Student name (ID) 1
Update footer with your name and id. Then delete this box.

ENG10004 Digital and Data Systems – Project Report
Design Tasks Details
1. Project tasks
 Describe your tasks in the group project
 Your design problem and requirements
2. Background research
 Knowledge needed
 Possible solutions to your problem
3. Final design solution
 Justify for final design decision made
 Analysis and results (e.g., drawing, flowchart, experimental graphs)
4. Conclusion and recommendation
 Conclude your achievement
 Recommend how you could further improve your results
5. Contributions to the group
 State how your efforts contribute to the whole group
 State how you involve in the teamwork environment
6. References
7. Appendices (optional)
Student name (ID) 2

ENG10004 Digital and Data Systems – Project Report
Reflective Journal
Week 3
Week 4
Week 5
Week 6
Week 7
Week 8
Week 9
Week 10
Week 11
Week 12
 Reflection on my learning experience (Answer the following questions)
1) What are the most important things you learnt from this project?
2) Did you meet your project goals?
3) What parts of the project do you particularly like? Why?
4) What do you find particularly challenging?
5) What are the things that helped you most in this project?
6) One thing I would like to improve upon is?
Student name (ID) 3

ENG10004 Digital and Data Systems – Project Report
Design Tasks Details
Project Tasks
Task Description in Group Project
Group project task entailed different activities to help design a porotype of a
building that will withstand earthquakes. The task adopted design steps of an
Engineering Design process in developing a tower of balsa wood and strings by using
other supplied material namely a motor Driver- x1, Accelerometer x2, sandbags, DC-
Motor x1, battery pack x1, charger x1 and a container x1. The group was required to
come up with a plan of a building and use the supplied materials to develop a building
structure that meets the features of withstanding an earthquake of a given frequency
level. Initially, group members greened enough background information on building
designs to help come up with means of measuring, making and determining the scope
of the project and the requirements that were to help come up with a perfect porotype
of a building.
Subsequently, the group members embarked in the actualization of the project
plan having understood the sequence of projects activities, the roles of each group
member, activity time frame (schedule and actual network), possible project
uncertainties, and the scope and projects objectives. The first step in the project
execution plan was to set up a structure that met the tower specifications. The
specifications included ensuring that the base of the tower did not exceed 225cm2 and
it stood on a shake table, the strings were attached to the bottom of the platforms, and
an open-air deck on the top was created to help hold the sandbag. Inspections were
implemented at every stage to ensure that the tower was lightweight to help reduce the
Student name (ID) 4

ENG10004 Digital and Data Systems – Project Report
number of material used. Note that, the above actualization process involved all group
members.
Moreover, each group member was to observe and supervise the action if not
directly involved. The participation was to help guide on any issue omitted during the
structuring of the tower. Consequential activities, namely measuring seismic waves
(vibrations) and the sustainability of the tower structure to different frequencies of the
waves were also included. A record was kept on each, and adjustable requirements
were made on the fabric to help realize the intended objective. Seismic waves were
measured after the group implemented, using the motor rotations, a way to generate
lethal movement on the shake table. The group members were to ensure the vibrations
were like a sinusoidal wave with the same frequency and amplitude above 500cm/s2of
25 cm, respectively. The final task was the presentation of the project, and it
demanded all members’ involvement and participation.
Design Problems and Requirements
The design problems involved meeting the specification in every project
phase. Initially, all group members had a better comprehension of the needs and
objectives of the project. But, it was a challenge to come up with a mechanism of
developing motor rotations that were to generate lethal movement on the tower
platform to resemble sinusoidal moves. Also, coding was challenging. These actions,
however, had initially demanded the considerations of the materials supplied and the
provided time frame as detailed in the initial project implementation phase. The
agreement was to set an amplitude of the waves at 2.0 cm and ensure the peak
accelerations close to 800 cm/s2. To the surprise of the members, the waves were far
beyond the sustainable ability of the first structure.
Student name (ID) 5

ENG10004 Digital and Data Systems – Project Report
A readjustment was done on the wave frequency by setting the rotations of the
motor much lower to generate waves which a new structure that had high lightweight
than the initial construction will sustain. A sustainable frequency was set above
500cm/ s2 and below the initial frequency level of 600 cm /s2 that merged with the
lightweight value of the structure. Altering the rotation of the motor within such
small frequency gap provided a challenge noting that the lethal vibrations of the tower
at the deck and base were to be measured at several changes. However, the
requirements were met, and the peak accelerations of the shake table were set above
500cm/s2, and different measures of the loads were tested to help determine the
deformation level and supporting capabilities of the tower.
Background Research
Knowledge Needed
The critical knowledge needed to be the understanding of building convolution
and impregnable earthquake frequency. The platform of shake table, as set in the
project, showed lateral vibrations created on the land surface and the effect the
movement creates on building structures. Earthquake is an adversity that has caused
deaths due to lack of proper building structures that can withstand the land vibrations
created by seismic waves of a shock. The effect has affected the sparse population,
and it relates to more social economic issues (Laghi et al. 2017). The knowledge on
earthquake occurrence helped to ensure that the tower had adjustable abilities that
absorbs the vibrations without creating any harmful effect that will result in collapsing
of the tower due to the resulting strain of the wave.
The need in the background study required the understanding of the generation
of the earthquake frequency and the lateral movement on the land surface starting
Student name (ID) 6

ENG10004 Digital and Data Systems – Project Report
from the epicenter of an earthquake to the stretching landscape affected by the seismic
waves. The group was needed to understand how such seismic waves shake the earth
service, their measures, and the relation to a building structure able to absorb the
vibrations without any harmful effect. The group had to know how to measure the
earthquake frequency and establish building structures that will sustain the earthquake
forces by regulating the sustainability ability and maximum load of a tower.
Understanding of the two issues was to help come up with a better structure that will
absorb the earthquake effects which needed another detailed research on the creative
building designs with adjustable abilities such as base isolations
Possible Solutions to the problem
The solution to the problem was to come up with an earthquake proof tower.
Background research provided different options on how to come up with such a tower.
The group learned on tuned mass dampers that reduced the swaying of the building.
More detailed research was done on base isolation strategy, which was applied in
developing the prototype. Base isolation system proved as one of the technique to
reduce the effects of an earthquake on building structures. The system included a
collection of structures that decouple a building structure from its resetting on a
shaking ground. The solutions proved significant since it increased the seismic
performance and sustainability of the tower considerably. However, there were other
more provided solutions such as including shock absorbers to the building to help the
tower remain relatively motionless virtual to the ground.
Final Design Solution
Justification of Final Design Decision
Student name (ID) 7

ENG10004 Digital and Data Systems – Project Report
The final design decision involved building a tower and isolating it from the
land surface(base platform). The group agreed on a base isolation system to provide
better building adjustable abilities. During an earthquake, as expressed in the porotype
development, base isolations help the building move more relative to the ground and
thus requires the creation of space between the architecture and the surrounding
landscape. It was noted that when all the utilities and connection to the building are
relatively flexible, they help the structure remain stable during an earthquake. The
movement frequency is, however, relative to the earthquake frequency on the surface
of the land. A tower can sustain the ground movement by moving a little or remaining
standstill during an earthquake.
Analysis and Results
The base tower area was exactly 225cm2, and it was set on a shake table with
strings attaching the base into the platform. The upper tower was created where
different sandbags were placed to include the live mass of the building. The rotating
of the motor resulted in sinusoidal waves with an amplitude of 2.9cm that kept
increasing and a resulting peak acceleration rate ranged from 500cm/s2to 600cm/s2.
(Measured by the accelerator sensors).
Tower Building Image
Student name (ID) 8

ENG10004 Digital and Data Systems – Project Report
Observation on the shake table, the Change of live loads and resulting tower Impact
Sand Bag Weight 2lbs 5lbs 8lbs 11lbs 14lbs
Acceleration at the
deck of the tower
(cm/s2)
510cm/s2 521cm/s2 532cm/s2 540cm/s2 565cm/s2
Acceleration rate at the
base of the tower
507
cm/s2
516 cm/s2 521 cm/s2 532 cm/s2 551 cm/s2
Building effect stable stable Slight
movement/
no effect on
attached
utilities
Slight
movement/
little effect on
the attached
utilities
Greater
movement/
effect on
utilities nut
stable
The deformation level of the tower with zero movements was determined as
follows
Student name (ID) 9

ENG10004 Digital and Data Systems – Project Report
PI1= Max (ǀAdeck- Abase ǀ)
= (521-516)
= 5 cm/s2
The deformation level of the tower with slight movement but no harmful
effect on the build was assessed at 14 cm/s2 (565-551) cm/s2). The tower supporting
capability was calculated as follows;
(The total mass of the tower was 35lbs, and the maximum mass placed on the
tower was 14 lbs)
PI2= MLoad /MTower
= (14/ 35)
= 0.4 lbs / 181.44grams
The tower was able to sustain the live load of 14lbs and remain stable at an
acceleration rate of 565cm/s2 at a and 552 cm/s2 at the deck and base of the tower
respectively. The decoupling of the tower allowed the tower to move with the shake
table frequency resulting in a minimal effect on the tower and the used utilities. At a
2lbs live load and low acceleration rate of 510 cm/s2 to 532cm/s2at the deck and base
of the tower were stable and had minimum effect on the utilities used. The space
between the shake table and the base area of the tower allow the tower to remain
stable even with the increased wave frequency and live load. However, the increase
in acceleration level led to a slight movement of the tower. The maximum live load
with a zero tower movement effect was14lbs with an acceleration rate of 521 cm/s2
and 516 cm/s2 at the deck and base of the tower respectively.
Conclusion and Recommendation
Student name (ID) 10

ENG10004 Digital and Data Systems – Project Report
Conclusion
The base isolation method proved capable of handling the effects of
earthquakes on building structures. If a building is built with flexible utilities and
enough space created on the building base and the surrounding group, the building
will slightly move or remain stagnant depending on earthquake frequency generated
from seismic waves. However, the stability of the structure depends on its location as
determined by the epicenter, the earthquake forces and spread of the impacts by
seismic waves (Primary, secondary and surface waves). The surface movement will
create a movement effect on the building, and if the building utilities used are flexible,
the building will move relative to the ground movement and remain guileless to the
earthquake effect. Therefore, an architectural building plan using base isolation
system can sustain the impact of an earthquake.
Recommendation
As determined in the project results, it is recommended a further study on
base isolation system and the relativity of the system to provide pure indemnity on
zero earthquake impacts on a building irrespective of any earthquake magnitude.
Establishing the extent of tower movement may depend on the base isolators, base
isolation, and the flexibility of the building utilities. However, there is still a limit of
building movement if an earthquake of higher frequency causes unstoppable seismic
waves with detrimental ground movement beyond building movement capability. The
effect may also depend on the maximum load (Live and dead load of the Building) at
the time of the earthquake. The assumptions may be applied vice versa.
It is also recommended for continual research on more possible solutions,
besides the base isolation technique, that will guarantee zero effect on building,
Student name (ID) 11